/Engine/Plugins/Runtime/GeometryProcessing/Source/GeometryAlgorithms/Public/Arrangement2d.h
Insert isolated point P into the arrangement when you know by construction it's not too close to any vertex or edge Much faster, but will break things if you use it to insert a point that is on top of any existing element!
int32 InsertNewIsolatedPointUnsafe ( const FVector2d & Pt )